Tip-over stability of omni-directional mobile robot

Dynamic stability of the mobile robot is a main concern for the safety of the system and the operator during the task. Due to the sudden dynamic changes during the operation, the system may tip-over or roll-over. This may cause unexpected injuries and damage to the system. This paper presents the dynamic coupled model of a manipulator and omni-directional platform equipped with mecanum wheels and its effect on the stability of the system. The dynamic model of the omni-directional mobile robot (Omni-WMR)has been developed to determine the torque developed at each link of the manipulator which causes a resultant force on each wheel of the platform responsible for the instability (tip-over) of the system. Finally, to avoid the tip-over of the system, the dimensions of the mobile platform are determined by Zero Moment Point (ZMP) approach.